1. Field of the Invention
The present invention relates to a photoelectric conversion device that converts light energy into electrical energy, and particularly relates to a photoelectric conversion device using crystalline semiconductor particles and a manufacturing method thereof.
2. Description of the Related Art
Solar cells with high conversion efficiency using monocrystalline or polycrystalline silicon wafers have been put to practical use. In particular, in response to global environmental issues in recent years, the market for residential photovoltaic systems and the like has expanded.
These solar cells are manufactured by being cut out of large silicon ingots. However, it takes a long time to manufacture large silicon ingots, which means productivity is low, and since supply of raw material of silicon itself is limited, the supply of silicon ingots is insufficient and cannot respond to the expansion of the market for solar cells.
Although amorphous silicon solar cells are known as solar cells that do not use large silicon ingots, conversion efficiency after stabilization remains low, and are unsuited to function as electrical power.
As a photoelectric conversion device that does not need a large silicon ingot, a photoelectric conversion device using silicon crystalline particles has been suggested (for examples, refer to Patent Document 1: Japanese Patent No. 2641800 and Patent Document 2: Japanese Published Patent Application No. 2005-159167). This photoelectric conversion device is based on a structure of providing and fixing a large number of one-conductivity type semiconductor particles over a substrate provided with a lower electrode or a substrate that becomes a lower electrode, and then forming a semiconductor layer that has an opposite conductivity type to the one-conductivity type, so that a p-n junction is formed.